Research On The Attenuation Of Electromagnetic Waves By Particles And Their Media

With the advancement of science and technology and the demand for equipment construction and social welfare,electromagnetic wave technology is widely used in various fields.For example,general radio communication for civilian or military,satellite communications,navigation,thermal imaging cameras,medical equipment and other fields are inseparable from electromagnetic wave technology.However,electromagnetic wave propagation in space will be attenuated by the interaction with particulate matter in the atmosphere,especially charged dust or charged particles,which will have a serious impact on the attenuation of electromagnetic waves and then affect the quality of signals during transmission.Therefore,based on the Mie scattering theory,the influence of charged particles on the electromagnetic wave scattering parameters,scattering phase function,and power attenuation was studied in this paper.Additionally,the experimental research on the attenuation of electromagnetic wave by the charged dielectric materials was carried out.The main research contents and innovations are as follows:Firstly,based on the Mie scattering theory,the scattering characteristics of charged particles,such as scattering efficiency,extinction efficiency,backscattering coefficient and scattering phase function are derived.It is found that there are obvious differences between the attenuation coefficient and the scattering phase function when the particles are charged or not,which is mainly reflected in that the attenuation coefficient and scattering phase function will change with the particle surface conductivity,particle surface charge distribution angle and particle size parameters.Secondly,based on 3D simulation software,a scattering model of charged particles is established;the influence rules of charged particles on scattering coefficient,extinction coefficient and radar scattering coefficient through simulation calculations are obtained.Meanwhile,the relationship between scattering phase function and surface charge density,charge distribution angle and azimuth angle of particles are obtained by simulation,as well.It is concluded that there is a critical value for the scattering phase function with the particle surface conductivity.If the value is larger than that,the dependence of the scattering phase function on the particle surface conductivity will increase.Finally,an experimental method for testing the attenuation performance of charged dielectric plates and films on electromagnetic wave propagation is proposed,and a test system is set up.an experimental study on the attenuation of electromagnetic waves by a charged dielectric plate and films is carried out.It was found that when the electromagnetic wave propagates through the dielectric plate or the charged dielectric plate,the attenuation of the electromagnetic wave energy will increase obviously with the increase of the charged amount.When the dielectric material is negatively charged,the effect is more obvious than when it is positively charged.